<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        /* 
        p{
            color:red;
            }
        .one{
             color:yellow;}
        #two{
            color:green;}
        伪类选择器
        p:hover{color:firebrick;}
        分组选择器
        */
    p,h1,div{
        color: royalblue;
    }
    </style>
</head>
<body>
    <p class="one" id="two">hello world</p>
    <h1>h1</h1>
    <div>div</div>
</body>
</html>